The mechanical characteristics of polytetrafluoroethylene (PTFE) polymers effect its overall performance characteristics including resistance to creep, ultimate strength, and flexural properties. For the polymer engineer, two of the major design issues encountered during the development of PTFE polymers are the ultimate strength and strength bias or uniformity of the material. It is known by those skilled in polymer design that amorphous PTFE polymer exhibit a bias or nonuniform strength characteristic due to the uniaxial orientation of the PTFE polymer chains. Polymer engineers have attempted to overcome this problem by making the amorphous PTFE polymer more crystalline via high temperature sinterring methods. Sinterring renders the polymer stiff and prone to flexure fatigue. Engineers have addressed the problems of amorphous PTFE nonuniform strength or strength bias by constructing layers of uniaxially orientated amorphous PTFE polymers. Layering renders the polymer prone to delamination problems and may make the polymer bulky and resistant to bending.
Multi-axial strength may be attained by thermally treating and subsequently coalescing PTFE polymers. This process results with a high crystallinity rendering the material stiff and prone to fracture fatigue and flex-life problems. Several manufacturers have introduced an expanded version of PTFE polymer characterized by crystalline fibrils and nodes such that the problems of stiffness arid flexure fatigue are minimized. While the expansion of PTFE does make the polymer less dense and thereby less stiff, continuous flexure of the crystalline fibrils may cause the fibrils to break rendering the material unsatisfactory for a variety of applications.
It is thus desirable to invent a novel PTFE polymer such that these problems are resolved.